Method to prepare a dental model

ABSTRACT

A method of producing a model of teeth and jaws by providing a base having holes into which at least two pins on each removable segment of the model extend and mounting the jaw impression on the base so that the bushings stick into the base after the base has hardened.

0 United States Patent 1 1 3,704,519

Lystager 1451 Dec. 5, 1972 [54] METHOD TO PREPARE A DENTAL 56] References Cited MODEL UNITED STATES PATENTS [72] Inventor: Gregers Lystager, Vedbaek,

Denmark 2,619,725 2/1952 Roeser ..32/32 3,498,580 3/1970 Wilson ..32/ll [73] Assignee: Whaledent, Inc., New York, NY.

- Primary ExaminerRobert Peshock M [22] Flled 8y 1971 Attorney-Burns, Doane, Swecker & Mathis [21] Appl. No.: 144,835

[57] 1 ABSTRACT [30] Foreign Application Priority Data A method of producing a model of teeth and jaws by providing a base having holes into which at least two May 27, 1970 Denmark ..2700/70 p on each removable Segment of the model extend and mounting the jaw impression on the base so that lll the bushing Stick into the base after the base has a p t t u u h d d. [58] Field of Search ..32/1 1, 40, 71 p at f 1 Claim, 1 Drawing Figure METHOD TO PREPARE A DENTAL MODEL The present invention relates to a method of construction of a model of teeth and jaws comprising a basis with removable tooth segments and dies, which are provided with pins to fit into matching holes in the basis.

Crown-and bridge works necessitate the use of a model fitting the teeth and jaws of a patient which makes it possible for instance to control dimensions and to make adjustments during the work in the absence of the patient.

Such a model is constructed on a basis of an impression of the teeth of the patient and usually consists of a basis fitting the jaws and of removable tooth impressions, so-called dies. 7 I

In known models the loose tooth impressions are attached to the basis by means of a conical pin which is inserted into each die on its underside and fitsinto its respective conical hole in the basis. To prevent the die from turning, the pin and the hole are elaborated with a non-circular cross-section.

It takes a long time to make such a model the use of which is inexpedient as even a small quantity of filth on a pin or in a" hole will cause, that the'die cannot be mounted correctly in relation to the other part of the model.

The object of the present invention is to provide a method of construction a model of the said kind by which it is possible to remove and remount individual dies repeatedly without risking that a remounted die has been wrongly placed.

According to the invention this is achieved by drilling in the ground plane of a jaw impression mutually parallel holes in such a number and being so placed, that there are in each part or die, which shall be removable in the model, at least two holes, that there is in each hole fixed a cylindrical pin with a bushing, and that the jaw impression is mounted on a not yet hardened basis with the bushings extending down into the basis material so that the bushings stick to the basis when same has set.

Pins and bushings may be fixed by means of an adequate adhesive material, or the impressions-and basismaterial may be of such a nature that it etches pins and bushings when set.

After the hardening the tooth impression may be removed from the basis and the individual dies separated by sawing out from the basis surface of the impression, which means that close-set preparations and delicate details in the collum area will not be damaged.

The dies may now be mounted on the basis whereby the ground plane separations effect an easy control as to whether the die has been correctly placed.

The invention will now be explained in further details with reference to the drawing showing a model of a jaw with a removed die.

The model shown in the drawing of the jaw of a patient has been made by drilling parallel holes in the ground plane of a jaw impression I in such a number and located in such a manner that there are two holes in each removable part or die 3 of the model. In each of these holes a cylindrical pin 4 with a bushing 5 is fixed.

The jaw impression I is then mounted on a not yet hardenedbasis 6 of gypsum with the bushings 5 extendlng down into the gypsum so that the bushings 5 stick to the basis 6, when the gypsum has hardened.

Between the impression I and the not hardened gypsum a suitable layer of separation is located so that the impression with the pins 4 may be lifted from the basis a 6 when the gypsum has set.

When the basis 6 has set, the impression I may be removed and sawn through so that each segment or die 3 has two pins 4. It is hereby a great advantage that the impression I can be sawn through from the surface with the pins as it is hereby possible to separate also close-set teeth.

In the model thus constructed the dies may, if necessary, be lifted from the basis and still retain the horizontal position, and an exact soldering control by constructing for instance bridges may be effected by placing the dies in the bridge anchors after which the individual die pins are to fit into their respective bushings in the basis.

Iclaim:

l. A method of constructing a model of teeth and jaws wherein die portions may be removed and remounted, said method comprising forming a model of a jaw impression having teeth on one surface and a ground plane on an opposite surface, drilling at least two parallel holes in said ground plane for each die portion which is desired to be removed, fixing a cylindrical pin in each of said holes with a free portion of each pin extending outwardly from said ground plane, disposing a bushing on each extending pin portion, mounting said model of a jaw impression on a not yet hardened member with said ground plane adjacent to a surface of said member and each bushing extending into said member surface, allowing said member to harden for securing each bushing in said member, removing said model of a jaw impression together with each pin from said hardened member with each bushing remaining fixed in said hardened member, and cutting die portions from said model of a jaw impression with each cut extending from said one surface to said opposite surface so that each die portion includes at least two pins. 

1. A method of constructing a model of teeth and jaws wherein die portions may be removed and remounted, said method comprising forming a model of a jaw impression having teeth on one surface and a ground plane on an opposite surface, drilling at least two parallel holes in said ground plane for each die portion which is desired to be removed, fixing a cylindrical pin in each of said holes with a free portion of each pin extending outwardly from said ground plane, disposing a bushing on each extending pin portion, mounting said model of a jaw impression on a not yet hardened member with said ground plane adjacent to a surface of said member and each bushing extending into said member surface, allowing said member to harden for securing each bushing in said member, removing said model of a jaw impression together with each pin from said hardened member with each bushing remaining fixed in said hardened member, and cutting die portions from said model of a jaw impression with each cut extending from said one surface to said opposite surface so that each die portion includes at least two pins. 